Separation unit and a dispenser comprising a separation unit

Abstract

A separation unit for separating a web material along preformed lines of weakness. The separation unit has a width direction and includes a first roller having a rotational axis extending in the width direction and a web width extending in the width direction, and a second roller having a rotational axis extending parallel with the rotational axis of the first roller and a web width extending in the width direction. The second roller is positioned at a distance from the first roller. Each of the first and the second rollers is provided with a plurality of protrusion elements being spaced along the rotational axes and protruding perpendicular from the axes. Each of the protrusion elements has a maximum width in the width direction, a maximum radial extension from the rotational axes, an inner portion adjacent to the rotational axes, and an outer portion remote from the rotational axes.

Claims

1. A method of loading a dispenser with a stack of a Z-folded web of paper having a plurality of longitudinally spaced preformed lines of weakness, the method comprising: providing or obtaining a dispenser having a separation unit, wherein the separation unit comprises: a first device having an axis extending in a width directions and a web width extending in said width direction, and a second device having an axis extending parallel with said axis of said first device, said second device being positioned at a distance from said first device, and a web width extending in said width direction, said distance extending in a direction perpendicular to said width direction, wherein each of said first and said second devices is provided with a plurality of protrusion elements being spaced along said axes and protruding perpendicularly from said axes, wherein each of said protrusion elements has a maximum width in said width direction, a maximum extension from said axes, an inner portion adjacent to said axes, and an outer portion remote from said axes, wherein said outer portions of said protrusion elements on said first device are arranged in a staggered relationship with said outer portions of said protrusion elements on said second device, and wherein said outer portions of said protrusion elements on said first device are partially overlapping with said outer portions of said protrusion elements on said second device with a overlap length, thus forming an undulating passage for a web material between said devices, wherein each protrusion element has a maximum width along the width direction within the overlap length, and the sum of said maximum widths within the overlap length of all protrusion elements on one of said devices is between 5-30% of said web width of that device, wherein the separation unit is configured to create a pinch force on the web material, wherein the separation of the web material along a preformed line of weakness comprises passage through the separation unit and the pinch force, and wherein the separation unit is configured to separate the web of paper along a preformed line of weakness with the pinch force; inserting a bundle in the form of the stack of the Z-folded web of paper in pre-folded form through a bottom section of the dispenser, the dispenser comprising a plurality of walls defining a reservoir for holding one or more bundles of pre-folded Z-folded web, and a dispensing opening, the dispenser extending vertically along a longitudinal dimension and horizontally along a width dimension; and wherein said Z-folded web of paper comprises at least a first web divided into sheet products defined between longitudinally separated lines of weakness extending across the first web; and at least a second web divided into sheet products defined between longitudinally separated lines of weakness extending across the second web; wherein the webs are interfolded so that the lines of weakness of the first web are offset from the lines of weakness of the second web in a longitudinal direction of the first web, wherein a sheet product from only one web is configured to be dispensed at a time.

2. The method of claim 1, wherein the bundle is the first of at least two bundles of Z-folded web in the reservoir of the dispenser, and wherein each of the at least two bundles has a connector on an end face thereof configured to attach a respective bundle to an adjacent bundle, the method further comprising: inserting a further bundle of Z-folded web in pre-folded form through the bottom section of the dispenser; and connecting the first bundle and the further bundle to one another by engaging the connector of the further bundle with the first bundle.

3. The method of claim 1, wherein the bundle is the first of at least two bundles of Z-folded web in pre-folded form in the reservoir of the dispenser, and wherein each of the at least two bundles has a connector on an end face thereof configured to attach a respective bundle to an adjacent bundle, the method further comprising: inserting a further bundle of Z-folded web through the bottom section of the dispenser; and connecting the first bundle and the further bundle to one another by engaging the connector of the first bundle with the further bundle.

4. The method of claim 1, wherein the bundle is the first of at least two bundles of Z-folded web in pre-folded form in the reservoir of the dispenser, and wherein each of the at least two bundles has a connector on an end face thereof configured to attach a respective bundle to an adjacent bundle, the method further comprising: inserting a further bundle of Z-folded web through the bottom section of the dispenser; and connecting the first bundle and the further bundle to one another by engaging the connector of the first bundle with the connector of the further bundle.

5. The method of claim 1, further comprising: guiding a leading portion of the Z-folded web upwardly toward a support roller adjacent a top wall of the dispenser; guiding the leading portion of the Z-folded web over the support roller and downward toward a separation unit of the dispenser comprising a first roller and a second roller, the first roller comprising a first plurality of discs spaced apart from one another, the second roller comprising a second plurality of discs spaced apart from one another, the first plurality of discs being offset in the width dimension with respect to the second plurality of discs, the first plurality of discs radially overlapping the second plurality of discs so as to define an undulatory path for the Z-folded web in the width dimension; guiding the leading portion of the Z-folded web between the first plurality of discs and the second plurality of discs; and extending the leading portion of the Z-folded web through the dispensing opening toward an exterior of the dispenser, and wherein the leading portion of the Z-folded web extends across a width of the dispensing opening without folding in a longitudinal direction of the Z-folded web due to the width of the dispensing opening.

6. The method of claim 5, wherein guiding the leading portion of the Z-folded web between the first plurality of discs and the second plurality of discs includes guiding the leading portion of the Z-folded web between the first plurality of discs and the second plurality of discs having a radial overlap in the range of about 2 to about 40 mm.

7. The method of claim 5, further comprising exerting a pulling force on the leading portion of the Z-folded web through the dispensing opening, the pulling force being effective to separate an individual sheet of paper from a remainder of the Z-folded web.

8. The method of claim 1, wherein the separation unit is configured to create a pinch force on the web of paper.

9. The method of claim 1, wherein the separation unit is configured to separate the web of paper along a preformed line of weakness without a sideways force.

10. A method of refilling a dispenser with a pre-folded refill bundle in the form of a stack of a Z-folded web of paper having a plurality of longitudinally spaced preformed lines of weakness, the method comprising: providing or obtaining a dispenser having a separation unit, wherein the separation unit comprises: a first device having an axis extending in a width directions and a web width extending in said width direction, and a second device having an axis extending parallel with said axis of said first device, said second device being positioned at a distance from said first device, and a web width extending in said width direction, said distance extending in a direction perpendicular to said width direction, wherein each of said first and said second devices is provided with a plurality of protrusion elements being spaced along said axes and protruding perpendicularly from said axes, wherein each of said protrusion elements has a maximum width in said width direction, a maximum extension from said axes, an inner portion adjacent to said axes, and an outer portion remote from said axes, wherein said outer portions of said protrusion elements on said first device are arranged in a staggered relationship with said outer portions of said protrusion elements on said second device, and wherein said outer portions of said protrusion elements on said first device are partially overlapping with said outer portions of said protrusion elements on said second device with a overlap length, thus forming an undulating passage for a web material between said devices, wherein each protrusion element has a maximum width along the width direction within the overlap length, and the sum of said maximum widths within the overlap length of all protrusion elements on one of said devices is between 5-30% of said web width of that device, wherein the separation unit is configured to create a pinch force on the web material, wherein the separation of the web material along a preformed line of weakness comprises passage through the separation unit and the pinch force, and wherein the separation unit is configured to separate the web of paper along a preformed line of weakness with the pinch force; inserting the refill bundle of the Z-folded web of paper through a bottom section of the dispenser comprising a plurality of walls defining a reservoir for holding one or more pre-folded bundles of Z-folded web, and a dispensing opening, the dispenser extending vertically along a longitudinal dimension and horizontally along a width dimension; and connecting the refill bundle of the Z-folded web of paper to an existing bundle of a Z- folded web of paper already in the reservoir, and wherein said Z-folded web of paper comprises at least a first web divided into sheet products defined between longitudinally separated lines of weakness extending across the first web; and at least a second web divided into sheet products defined between longitudinally separated lines of weakness extending across the second web; wherein the webs are interfolded so that the lines of weakness of the first web are offset from the lines of weakness of the second web in a longitudinal direction of the first web, wherein a sheet product from only one web is configured to be dispensed at a time.

11. The method of claim 10, wherein the radial overlap length is about 2 to about 40 mm.

12. The method of claim 10, wherein the first bundle and the refill bundle each have a connector on an end face thereof configured to attach a respective bundle to an adjacent bundle, the method comprising: connecting the refill bundle and the existing bundle to one another by engaging the connector of the existing bundle with the refill bundle.

13. The method of claim 10, wherein the first bundle and the refill bundle each have a connector on an end face thereof configured to attach a respective bundle to an adjacent bundle, the method comprising: connecting the refill bundle and the existing bundle to one another by engaging the connector of the refill bundle with the connector of the existing bundle.

14. The method of claim 10, wherein the first bundle and the refill bundle each have a connector on an end face thereof configured to attach a respective bundle to an adjacent bundle, the method comprising: connecting the refill bundle and the existing bundle to one another by engaging the connector of the refill bundle with the existing bundle.

15. The method of claim 10, wherein the existing bundle has: a portion guided upwardly over a support roller adjacent a top wall of the dispenser and downward to a separation unit of the dispenser comprising a first roller and a second roller, the first roller comprising a first plurality of discs spaced apart from one another, the second roller comprising a second plurality of discs spaced apart from one another, the first plurality of discs being offset in the width dimension with respect to the second plurality of discs, the first plurality of discs radially overlapping the second plurality of discs, the portion being guided between the first plurality of discs and the second plurality of discs so that the portion has an undulatory path in the width dimension, and extended through the dispensing opening toward an exterior of the dispenser, wherein, upon connecting, a leading portion of the refill bundle is configured to be: guided upwardly toward the support roller adjacent the top wall of the dispenser; guided over the support roller and downward toward the separation unit of the dispenser; guided between the first plurality of discs and the second plurality of discs to thereby cause the first roller and the second roller to rotate; and extended through the dispensing opening toward an exterior of the dispenser, wherein the leading portion of the Z-folded web is configured to be extended across a width of the dispensing opening without folding in a longitudinal direction of the Z-folded web due to the width of the dispensing opening.

16. The method of claim 10, wherein the separation unit is configured to separate the web of paper along a preformed line of weakness without a sideways force.

17. The method of claim 10, wherein the separation unit is configured to create a pinch force on the web of paper.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which: FIGS. 1a, 1b and 1c show a separation unit according to the present invention; FIG. 2 shows the separation unit according to the present invention seen in the width direction; FIG. 3 shows protrusion elements having different dimensions and differently shaped outer portions; FIGS. 4 and 5 show a dispenser comprising the separation unit according to the present invention;

(2) FIG. 6 shows a web material with a first web layer divided into sheet products defined between longitudinally separated preformed lines of weakness extending across the first layer and a second web layer divided into sheet products defined between longitudinally separated lines of weakness extending across the second web layer. The web layers are interfolded so that the lines of weakness of the first web layer are offset from the lines of weakness of the second web layer in a longitudinal direction.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(3) FIGS. 1a and 1b show a separation unit 1 according to the present invention. The separation unit 1 comprises a first roller 2 and a second roller 3, each extending in a width direction and comprising plurality of protrusion elements 4 being spaced along the rollers 2, 3 and protruding perpendicular from the rollers 2, 3. The rollers 2, 3 are positioned at a distance d.sub.1 from each other, wherein the distance d.sub.1 is extending in a direction perpendicular to the width direction of the rollers 2, 3. In the embodiment shown in FIG. 1a, the first roller 2 comprises six protrusion elements 4, and the second roller 3 comprises four protrusion elements 4. The separation unit 1 has a web width W.sub.w (FIG. 1c). Each of the protrusion elements 4 has a maximum width W.sub.pe in the width direction and a maximum radial extension r from the rollers 2, 3. In the embodiment shown in FIG. 1a, the maximum widths W.sub.pe and the maximum radial extensions r of all the protrusion elements 4 are the same. Each protrusion element has an inner portion 6 adjacent to the rollers 2, 3, and an outer portion 5 remote from the rollers 2, 3, wherein the outer portions 5 of the protrusion elements 4 on the first roller 2 are arranged in a staggered relationship with the outer portions 5 of the protrusion elements 4 on the second roller 3, which is best seen in FIG. 2. The outer portions 5 of the protrusion elements 4 have a slightly curved shape. The outer portions 5 of the protrusion elements 4 on the first roller 2 are partially overlapping with the outer portions 5 of the protrusion elements 4 on the second roller 3 with a radial 15 overlap length L. Such a configuration of the protrusion elements forms an undulating passage for a web material between the rollers 2, 3 (FIG. 1c).

(4) In the embodiment shown in FIGS. 1a and 1b, no protrusion elements are placed in the central portion C of the rollers 2, 3. Such an arrangement of the protrusion elements allows the user to easily access the leading end of the web material 16 in the central portion C of the separation unit 1 (FIG. 1c).

(5) As may be seen in FIGS. 1a and 1b, the spacing d.sub.2 between each two protrusion elements 4 is equal to or greater than the maximum width w of each protrusion element 4. Such a configuration enables the protrusion elements 4 to be relatively scarcely distributed, which provides an optimal pinch force.

(6) Another advantageous feature of the separation unit according to the present invention is that the maximum radial extensions r of the protrusion elements are equal to or greater than the maximum widths W.sub.pe of the protrusion elements. As may be seen in FIGS. 1a and 1b, the protrusion elements are formed as relatively large and thin discs, which optimizes the pinch force.

(7) FIG. 2 illustrates the separation unit 1 seen in the width direction. It is clearly shown that the outer portions 5 of the protrusion elements 4 on the first roller 2 overlap with the outer portions 5 of the protrusion elements 4 on the second roller 3.

(8) As previously mentioned, the protrusion elements 4 may have different maximum widths W.sub.pe and maximum radial extension r. In FIG. 3, protrusion elements having different maximum widths W.sub.pe and different maximum radial extensions r are shown.

(9) As mentioned above, the shape of the outer portions 5 of the protrusion elements 4 may vary. In FIG. 3, four other possible shapes of the outer portions 5 are depicted. Thus, the outer portions may have smooth surface, or may be provided with ribbed surface. As will be understood by the person skilled in the art, if the surfaces of the outer portions of the protrusion elements are ribbed, the friction between the web material and the outer surfaces of the protrusion elements, and thus the pinch force, is greater compared to the friction provided by smooth surfaces.

(10) FIG. 4 schematically shows a dispenser 7 with a separation unit 1 according to the present invention. The dispenser 7 has an outer front wall 8, two outer side walls 9 and a housing 10. The housing 10 is intended for holding a pile of a continuous length of accordion-like folded web of towels of tissue paper or nonwoven comprising bundles 12 of a continuous length of accordion-like folded web of towels of tissue paper or nonwoven. The bundles 12 comprise connecting means 13a, 13b between the bundles 12. The dispenser 7 comprises a guiding element 14 in the form of a curved plate which extends over a segment of the web-supporting roller surface 15. The at least one web 16 is arranged to be fed through the guiding element 14 when the dispenser 7 is in use, and at least one part of the guiding element 14 is arranged to bear against the web 16. The guiding element 14 thereby holds the at least one web 16 in place on the roller surface 15 so that it does not move backwards or sidewards during the use of the dispenser, or in case of web-breakage.

(11) The unit subsequent to the guiding element 14 is separation unit 1 described above. The separation unit 1 provides an optimal pinch force acting on the web material 16, and allows the web material 16 to be separated at the desired position. The separation unit 1 depicted in FIG. 4 is configured such that both of the rollers 2, 3 are positioned inside the housing 10. It is also conceivable that one of the rotational axes is located in the outer front wall 8, such that when the outer front wall 8 is opened, the pinch force caused by the separation unit 1 is released.

(12) The dispenser 7 illustrated in FIG. 4 comprises a stack of interfolded webs 16, whereby the dispenser 7 is configured so that a preceding stack of interfolded webs in the housing 10 has to be lifted to position a new, succeeding stack in the housing 10 underneath the preceding stack to refill the dispenser 7. Stacks of interfolded webs in the dispenser 7 may be interconnected via connecting means 13a, 13b, such as adhesive, adhesive tape or mechanical fasteners, such as hook and loop fasteners, at the bottom and/or top of each of the refill stacks. The web 16 is arranged to be fed upwards within the housing 10, around the roller 15 located at the top of the dispenser 7 and downwards towards the separation unit 1 and the dispensing opening 17.

(13) In FIG. 5 the dispenser 7 is depicted in the state when no web material 16 is loaded. The separation unit 1 is positioned within the housing 10 at the same level as the dispensing opening 17, such that the perforated web 16 is separated along the preformed lines of weakness at the moment of dispensing with almost no effort from the user's side.

(14) It should be noted that the dispenser 7 according to the present invention may be any type of automatic or non-automatic dispenser for dispensing at least one web, i.e. a plurality of webs may be dispensed simultaneously, or a plurality of different webs may be dispensed by the dispenser 7 one at a time.

(15) The dispenser 7 is a free-standing, but the dispenser may also be mounted on any suitable object in any suitable manner. Furthermore, a dispenser housing 10 of a dispenser according to the present invention need not necessarily contain an entire web 16 that is to be dispensed by the dispenser 7. At least one web 16 may for example be stored outside the housing 10 and merely be fed through the housing 10 when the dispenser 7 is in use.

(16) FIG. 6 shows a web material 616 with a first web layer 620 divided into sheet products defined between longitudinally separated preformed lines of weakness 621 extending across the first layer 620; and at least a second web layer 625 divided into sheet products defined between longitudinally separated lines of weakness 626 extending across the second web layer 625. The web layers 620, 625 may be interfolded so that the lines of weakness 621 of the first web layer 620 are offset from the lines of weakness 626 of the second web layer 625 in a longitudinal direction.

(17) Although the present invention has been described with reference to various embodiments, those skilled in the art will recognize that changes may be made without departing from the scope of the invention. It is intended that the detailed description be regarded as illustrative and that the appended claims including all the equivalents are intended to define the scope of the invention.

EMBODIMENTS

(18) 1. A separation unit for separating a web material along preformed lines of weakness, said separation unit having a width direction and comprising a first roller having a rotational axis extending in said width direction and a web width extending in said width direction, and a second roller having a rotational axis extending parallel with said rotational axis of said first roller and a web width extending in said width direction, said second roller being positioned at a distance from said first roller, said distance extending in a direction perpendicular to said width direction, wherein each of said first and said second rollers is provided with a plurality of protrusion elements being spaced along said rotational axes and protruding perpendicularly from said axes, wherein each of said protrusion elements has a maximum width in said width direction, a maximum radial extension from said rotational axes, an inner portion adjacent to said rotational axes, and an outer portion remote from said rotational axes, wherein said outer portions of said protrusion elements on said first roller are arranged in a staggered relationship with said outer portions of said protrusion elements on said second roller, and wherein said outer portions of said protrusion elements on said first roller are partially overlapping with said outer portions of said protrusion elements on said second roller with a radial overlap length, thus forming an undulating passage for a web material between said rollers, characterized in that each protrusion element has a maximum width along the width direction within the overlap length, and the sum of said maximum widths within the overlap length of all protrusion elements on one of said rollers is between 5-30%, preferably 12-20% of said web width of that roller. 2. The separation unit according to embodiment 1, wherein said protrusion elements have different maximum radial extensions and/or different maximum widths. 3. The separation unit according to embodiment 1, wherein said protrusion elements have same maximum radial extensions and same maximum widths. 4. The separation unit according to anyone of the preceding embodiments, wherein said spacing between each two protrusion elements is equal to or greater than said maximum width of each protrusion element. 5. The separation unit according to anyone of the preceding embodiments, wherein said maximum radial extensions of said protrusion elements are equal to or greater than said maximum widths of said protrusion elements. 6. The separation unit according to anyone of the preceding embodiments, wherein said maximum radial extensions of said protrusion elements are between 5-50 mm, preferably 5-30 mm, more preferably 10-20 mm, or most preferably 12-18 mm. 7. The separation unit according to anyone of the preceding embodiments, wherein the maximum widths of said protrusion elements are between 4-20 mm, preferably 5-10 mm, most preferably 6-8 mm. 8. The separation unit according to anyone of the preceding embodiments, wherein said protrusion elements are arranged with same spacing in different parts of said first and/or said second roller. 9. The separation unit according to embodiments 1-7, wherein at least one of said first and said second rollers comprises at least a first, a second and a third protrusion element, wherein the spacing between said first and said second protrusion elements along the width direction of said first and/or said second roller differs from the spacing between said second and said third protrusion elements along the width direction of said first and/or said second roller. 10. The separation unit according to embodiments 1-7, wherein each of said first and said second rollers has a central portion and outer portions in said width direction, and wherein said spacing between said protrusion elements is greater in said central portion than in said peripheral portions. 11. The separation unit according to anyone of the preceding embodiments, wherein said radial overlap length is between 2-40 mm, preferably 2-20 mm, more preferably 3-12 mm, or most preferably between 4-10 mm. 12. The separation unit according to anyone of the preceding embodiments, wherein said distance between said rotational axes of said first and said second rollers is between 8-100 mm. 13. The separation unit according to anyone of the preceding embodiments, wherein said protrusion elements are formed integral with said first and/or second roller. 14. The separation unit according to embodiments 1-13, wherein said protrusion elements are separate units attached to said first and/or second roller. 15. The separation unit according to anyone of the preceding embodiments, wherein said distance between said rotational axes of said first and said second rollers is adjustable. 16. The separation unit according to embodiment 15, wherein said adjustment is enabled by biasing means. 17. The separation unit according to anyone of the preceding embodiments, wherein said protrusion elements are disc elements. 18. The separation unit according to anyone of the preceding embodiments, wherein said outer portions of said protrusion elements have ribbed surfaces. 19. A dispenser for a web material, comprising a housing defining a web material reservoir; a dispensing opening; a control unit; a separation unit according to anyone of the embodiments 1-18. 20. The dispenser according to embodiment 19 for containing a web material comprising preformed lines of weakness, said web material being Z-folded to form a stack. 21. The dispenser according to embodiment 19 for containing a web material comprising preformed lines of weakness, said web material being in the form of a roll. 22. The dispenser according to anyone of embodiments 19-21, wherein the dispenser further comprises a feeding mechanism. 23. The dispenser according to anyone of embodiments 19-22, wherein said web material is contained in said reservoir, and wherein a leading portion of said web material is supported in a dispensing path from said reservoir to said dispensing opening. 24. The dispenser according to embodiment 23, wherein said leading portion extends upwardly from the top of the said stack of said web material. 25. The dispenser according to anyone of embodiments 19-24, wherein said preformed lines of weakness are perforation lines formed by alternating bonds and slots and having the perforation strength between 20-80 N/m, preferably 30-45 N/m. 26. The dispenser according to anyone of embodiments 19-25, wherein said web material comprises at least a first layer divided into sheet products defined between longitudinally separated lines of weakness extending across the first layer; and at least a second elongate web divided into sheet products defined between longitudinally separated lines of weakness extending across the second layer; wherein the webs are interfolded so that the lines of weakness of the first web are offset from the lines of weakness of the second web in a longitudinal direction of the first web.